The invention relates to hinges, and more particularly, to barrel hinges.
Barrel hinges are widely used in applications that require hingeably attaching heavy structures together, such as ingress and egress ramps for horse trailers, ramps for earth-moving equipment trailers, doors for ocean shipping containers, and the like.
In order to provide for lubrication of barrel hinges, grease fittings can be included in the hinge designs by being attached to ends of a shaft, with a grease channel provided through the shaft so that grease can be released between the pin and the sleeve. However, for long barrel hinges, it can be costly and difficult to bore a grease channel through the pin for delivery of grease between the pin and the sleeve of the barrel hinge.
Prior art barrel hinges having three sleeve sections have been made by providing three separate sleeves made of seamless tubing and an elongate rod which is retained within bores of the sleeves. Once assembled, the two end sleeves are welded at their ends to the ends of the rod, leaving the intermediate sleeve to freely rotate. These welds require additional labor and are more prone to corrosion than the unwelded portions. These prior designs do not lend themselves to lubrication by use of the grease fitting and therefore requires manual frequent lubrication, or more typically, remain unlubricated. Furthermore, seamless tubing is more costly than seamed tubing.
Accordingly, there remains a need for an improved barrel hinge that is easier to manufacture and maintain, is less prone to rust, has better lubrication properties, and has more consistent quality.